JPH039090B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a therapeutic agent for diabetic nephropathy containing elastase as an active ingredient. In recent years, there have been significant advances in the treatment of diabetes, including the development of purified insulin preparations, human insulin, and artificial pancreas.However, the currently commonly used treatments for diabetes include dietary therapy, oral hypoglycemic agents, and insulin. The concomitant use of subcutaneous injections cannot completely prevent the development of diabetic microangiopathy. In particular, diabetic nephropathy, which is a type of microangiopathy, is one of the leading causes of death in diabetic patients and is emphasized as a factor that influences the prognosis of diabetic patients. The most influential theory as to the cause of diabetic nephropathy is the metabolic abnormality theory, and in order to prevent nephropathy, it is fundamentally necessary to correct the metabolic abnormality, that is, to completely overcome diabetes. However, at present,
Complete correction of metabolic abnormalities cannot be expected except by methods such as using an artificial pancreas, and therefore, it is necessary to prevent nephropathy by forcing some degree of metabolic abnormality. Conventionally, pituitary gland destruction, kidney transplantation, non-steroidal anti-inflammatory drugs, anticoagulant therapy, etc. have been used.
No definitive or effective treatment method has been established, and at present, artificial dialysis is performed for cases that eventually progress to renal failure. In view of these circumstances, the present inventors have investigated drugs for alleviating or treating diabetic nephropathy, particularly drugs that reduce proteinuria and serum urea nitrogen, which are the clinical chemical characteristics of diabetic nephropathy. Ta. As a result, they discovered that elastase is a drug that achieves this objective, and have completed the present invention. That is, an object of the present invention is to provide a drug that alleviates or treats diabetic nephropathy, and particularly reduces proteinuria and serum urea nitrogen, which are the clinical chemical characteristics of diabetic nephropathy. Elastase is an enzyme that specifically decomposes elastin, a hard protein that is insoluble in water, and is produced industrially by extraction from pig pancreas. Its characteristics are as follows. First, the molecular weight is 25900 (value determined from the amino acid sequence based on the primary structure), and the isoelectric point is PH9.5±0.5
and the sedimentation coefficient S ₂₀ , w is 2.6. Regarding activity, serine and histidine are present in the active center, and in addition to elastin, it specifically decomposes N-α-benzoyl-L-alanine methyl ester or acetyl-L-trialanine paranitroanilide as a synthetic substrate. There is a tendency to
According to the results of measurements using N-α-benzoyl-L-alanine methyl ester as a substrate, the activity was optimal.
PH is 8-10, especially around 8.8. Also, NaCl,
Its activity is inhibited by KCl, (NH ₄ ) ₂ SO ₄ , NaCN, and CuSO ₄ . The activity is also inhibited by certain N-α-benzoylcarboxy derivatives. Furthermore, biochemically, β-lipoproteinase activity and lipoprotein lipase activity have been observed.
It has the effect of normalizing lipid metabolism abnormalities in serum and tissues. Therefore, it is clinically used to improve hyperlipidemia and serum lipid abnormalities associated with arteriosclerosis.
It also acts on the artery wall itself, reducing its elasticity and
Maintains and promotes extensibility. In other words, it has the function of removing degenerated elastin from the arterial wall, promoting the production of fresh elastin, and suppressing the deposition of fat on degenerated elastin, thereby preventing the occurrence of atherosclerosis. The following documents 1) to 3) are listed for reference. 1 Kazuo Ogawa, Yasuhiro Ago: Morphological study on the anti-atherosclerotic effect of Elastase, Nichiro Medical Journal, 10:
277-292 (1973) 2 Asahi Osawa: Elastase (elastic fiber degrading enzyme)
Regarding the anti-arteriosclerotic effect of
-29 (1970) 3 Tomoyuki Naito, Toshio Higashino, Tsutomu Iwabuchi, Yoshie Ishimaru, Akihide Uesugi, Michio Ogasawara, Ryomasa Omori, Masao Kase, Hitoshi Kimura, Riyasu Shichi, Saburo Yokoyama: Evaluation of elastase by double-blind test. Study on the effect of improving serum lipid abnormalities, History of Medicine, 82: 848-859 (1972) Taking all of its functions together, elastase can be used effectively not only for hyperlipidemia, arteriosclerosis, and hypertension, but also for diabetes. It is clear that it can be done. For example, it has recently been shown that elastase suppresses morphological lesions seen in renal glomeruli, such as basement membrane thickening, in spontaneously diabetic KK mice;
It has been reported that in NSY mice, not only was the increase in basement membrane thickening similarly suppressed, but there was even a tendency for basement membrane thickening to be reduced. The following documents 4) to 6) are listed for reference. 4 Shinichi Oikawa, Masae Kakizaki, Yoshio Goto: Suppression of glomerular basement membrane thickening in spontaneously diabetic rat kidneys by pancreatic elastase, History of Medicine, 111: 583-584
(1979) 5 Nobuhiro Kaseda: Elastase effect on early renal lesions in spontaneously diabetic KK mice - Morphological observation by electron microscopy -, Clinical Adult Disease 7: 133-139
(1977) 6 Akio Shida, Atsuko Kawada, Tsuneki Kishi, Kaizo Kobayashi,
Fumiji Yasuda, Tsuneharu Kuno, Minoru Sasaki: Effect of elastase on glomerular lesions in spontaneously diabetic NSY mice, Nagoya.J.Med.Sci.43:111
(1981) However, these findings are based on diabetes in animals such as rats and mice, and it is not known whether elastase is effective against the nephropathy that develops in human diabetes. . In 1936, Klmmelstiel and Wilson recognized nodular sclerotic lesions in the renal glomeruli as a morphological change in the kidneys associated with diabetic nephropathy. Since then, renal glomerular lesions have attracted attention and many reports have been made. The earliest morphological change observed in diabetic renal glomeruli is thought to be thickening of the basement membrane of the glomerular loop wall. However, it was not known whether elastase is effective in reducing urine protein and serum urea nitrogen, which are the clinical chemical characteristics of human diabetic nephropathy. Under such circumstances, the present invention has pioneered new knowledge in the field of treatment of diabetic nephropathy, and has the potential to therapeutically reduce urinary protein and serum urea nitrogen, which have traditionally been difficult to eliminate in this nephropathy. Its usefulness and inventive step can be recognized in that it can reduce the amount of waste. The present invention will be explained below. Diabetic nephropathy according to the present invention is nephropathy that develops with diabetes, and although it is difficult to define it accurately, it includes, for example, cases that satisfy the following three diagnostic criteria. However, the present invention is not limited to this case. (1) There is no history of renal disease such as nephritis or nephrotic syndrome (primary), or lesions that cause prerenal proteinuria such as heart failure or postrenal proteinuria such as pancreatic cystitis.
Having persistent proteinuria. (2) No significant abnormalities such as cast urine or hematuria should be observed in the urine sediment findings. (3) Diabetic retinopathy preceded by persistent proteinuria. In the present invention, elastase is administered orally. Furthermore, after being orally administered, elastase is absorbed into the intestinal wall and transported to the blood via the portal vein and lymphatic vessels. In serum, α ₂ -macroglobulin and α ₁
- It binds to antitrypsin, is widely distributed in all tissues, is metabolized mainly in the liver, and is excreted in the urine. The blood concentration reaches its maximum value 6 hours after administration, and the area under the blood concentration curve, which indicates the amount absorbed into the blood, increases in proportion to the dose. Next, in the present invention, the daily dosage of elastase is, for example, 5,000 to 5,000 per day per diabetic nephropathy patient.
20,000 EL.U. (elastase units), and it is preferable to administer this dose continuously for, for example, 4 to 20 weeks. However, the present invention is not particularly limited to the above described range. The acute toxicity of elastase is shown in the table below.

[Table] Other toxicity is as shown by the following experiments. Subacute toxicity: 750, 7500, 37500 to male and female Wister rats.
75,000, EL.U./Kg/day was administered orally for 4 weeks, and 900, 4,500 EL.U./Kg/day was continuously administered orally to male and female beagle dogs for 12 weeks. As a result, the general condition of both rats and beagles was
No noteworthy abnormal findings were observed in blood, urine tests, or morphological observations (macroscopically or histologically). Chronic toxicity to male and female Wistar rats 2250, 5700, 11250,
22500 EL.U./Kg/day was orally administered for 24 weeks. As a result, no noteworthy abnormal findings were observed in general conditions, blood and urine tests, and morphological observations (macroscopically and histologically). Teratogenicity 750 during organogenesis in pregnant mice and rats.
7500, 75000 EL.U./Kg/day was administered orally for 6 consecutive days. As a result, no lethal, growth-suppressing, or teratogenic effects on fetuses, and no effects on morphological or functional differentiation of newborns were observed. Since the therapeutic agent of the present invention is administered orally,
It is preferable to use a dosage form suitable for this purpose, for example, a solid oral preparation such as granules, tablets, and capsules. Solid preparations may be produced by conventional methods using excipients commonly used in the field of pharmaceutical technology. Thus, for example, the binder may be added directly to a mixture of elastase, lactose, starch and cellulose, or added during fluidized bed spraying to form granules, and the resulting granules may be filled into capsules. The effects of the present invention will be explained using the following experimental examples. Experimental example Subjects and methods The subjects were 13 patients (8 males) with diabetic nephropathy.
The details are shown in Table 1. Diagnosis of diabetic nephropathy was limited to cases that satisfied all of the following three items. (1) No history of renal disease such as nephritis or nephrotic syndrome (primary), or lesions that cause prerenal proteinuria such as heart failure or postrenal proteinuria such as cystitis;
Having persistent proteinuria. (2) No significant abnormalities such as cast urine or hematuria should be observed in the urine sediment findings. (3) Diabetic retinopathy preceded by persistent proteinuria. Elastase per day for the above cases
Administered at a rate of 10800EL.U for 12 weeks, urine before and after administration

[Table] Daily protein excretion and serum urea nitrogen were measured. In addition, fasting blood sugar, serum creatinine, and serum lipids (total cholesterol, triglycerides) were measured for reference. Results The results are shown in Table 2 and Figure 1. (1) Change in urine protein amount In Table 2, when comparing the daily urine protein excretion amount before and after elastase administration, in 5 out of 13 cases,
After administration of elastase, a significant decrease was observed, and the remaining 8
A decreasing trend was also observed in 6 of the cases. (2) Serum urea nitrogen In Table 2, serum urea nitrogen decreased in 10 out of 13 cases, and 3 out of 5 cases showed a significant decrease in urine protein.
A decrease is also observed in this example. (3) Others In Table 2, serum creatinine decreased in some cases, but remained almost unchanged overall. Looking at the changes in fasting blood sugar (average value of 3 to 4 times each) before and after elastase administration, it was found that in all cases,

【table】

[Table] No significant changes were observed. Furthermore, as shown in FIG. 1, there were no cases in which serum total cholesterol and triglyceride levels showed abnormally high values before elastase administration, and no significant increase or decrease was observed after administration. In addition, no side effects thought to be caused by this drug were observed in any of the cases. The present invention will be explained in more detail with reference to Examples described below. Example 1 100 g of elastase (85EL.U/mg) and 400 g of sucrose fatty acid ester were lightly ground into a uniform powder. This contains 500 spray dried lactose.
g, crystalline cellulose 495g, CMC calcium 300
g and mixed. Next, 5 g of calcium stearate was sprinkled through an 80-mesh sieve, mixed evenly, and tableted to produce tablets with a diameter of 8 mm and a weight of 180 mg, which were used as a therapeutic agent for diabetic nephropathy. Example 2 Nonpareil 2.5Kg HPC-L 0.5Kg Ethanol Appropriate amount Elastase (85EL.U./mg) 0.6Kg Sucrose fatty acid ester 1.5Kg Corn starch 2.7Kg HP-55 1.95Kg Acetyl monoglyceride 0.25Kg Ethanol Appropriate amount was loaded, and while spraying an ethanol solution of HPC-L, a mixed powder of elastase, sucrose fatty acid ester, and cornstarch was spread and granulated. The granulated granules were spray-coated with an ethanol solution of acetyl monoglyceride and HP-55 using the same equipment to produce enteric-coated granules. Note that Nonpareil is a mixture of sucrose and corn starch, HPC-L is hydroxypropyl cellulose, and HP-55 is hydroxypropyl methyl cellulose phthalate.

[Brief explanation of the drawing]

FIG. 1 is a drawing corresponding to FIG. 1 described in the section of Experimental Example 1 Results.

Claims (1)

[Claims] 1. A therapeutic agent for diabetic nephropathy containing elastase as an active ingredient.